Compartmentalization in a prebiotic setting is an important aspect of early cell formation and is crucial for the development of an artificial protocell system that effectively couples genotype and phenotype. Aqueous two-phase systems ATPSs and complex coacervates are phase separation phenomena that lead to the selective partitioning of biomolecules and have recently been proposed as membrane-free protocell models. We show in this study through fluorescence recovery after photobleaching FRAP microscopy that despite the ability of such systems to effectively concentrate RNA, there is a high rate of RNA exchange between phases in dextran-polyethylene glycol ATPS and ATP-poly-L-lysine coacervate droplets. In contrast to fatty acid vesicles, these systems would not allow effective segregation and consequent evolution of RNA, thus rendering these systems ineffective as model protocells.

KeywordsPrebiotic chemistry Phase separation Compartmentalization Aqueous two-phase systems Coacervates Origin of life Electronic supplementary materialThe online version of this article doi:10.1007-s11084-014-9355-8 contains supplementary material, which is available to authorized users.